Paisagens polares não glaciais (proglacial, paraglacial e periglacial): revisão de conceitos e contribuições da pesquisa pedogeomorfológica brasileira

Abstract

The paper proposes a discussion about origin and evolution of proglacial, paraglacial and periglacial concepts. It aims to show diff erentiation of landforms, process, questions and also the critiques that are unique of each other. Over the years the three terms have been made redundant and employed in an overlapping manner, even that they are quite diff erent concepts and are defi ned in quite diff erent ways. Furthermore, in spite of the growing participation of Brazilian researchers in Antarctica the epistemological issues about these environments still remains as a gap in national publications. The proglacial landscape is pioneer in receiving the glaciated products and it is a primarily depositional environment. Such environments are totally adjusted to the regime of fl uvial, marine and lacustrine processes that occur immediately adjacent to the glacier and consequently the proglacial domain follows the movement of the ice margin. The paraglacial landscape it is not defi ned by location or processes, but by trajectory from glacial to non-glacial environment. Thus, the diagnostic criteria is time, and the paraglacial environment is in recovering from the disturbance of glaciation. The periglacial realm is defi ned primarily by freeze-thaw cycles and deep seasonal freezing. The presence of permafrost is not required.